The information described in this background section is not admitted to be prior art.
Three-dimensional integrated circuits (3D-ICs) comprise vertically stacked semiconductor dies optionally positioned on interposer substrates. The vertically stacked semiconductor dies can be electrically connected to each other using through-silicon vias (TSVs) that extend through the thickness dimensions of the semiconductor dies and/or the optional interposer substrates, which are both generally made from silicon wafers. TSVs provide a higher performance interconnect between dies and other electronic devices in 3D-ICs and other 3D microelectronic packages. The higher performance derives from the higher via densities and shorter connection lengths provided by TSV-based architectures, which produce higher transmission speeds and lower power consumption. TSV-based 3D-ICs and other 3D microelectronic packages can also improve form factor with decreased system volume, mass, and footprint.
Notwithstanding their performance advantages, the use of TSVs in 3D-ICs and other 3D microelectronic packages can be disadvantageous in a number of respects. For instance, TSV-based 3D-ICs and package designs are relatively complex compared to conventional 2D counterparts and require more sophisticated design techniques and tools. In an active die, the physical size of a TSV (e.g., 15-30 micrometer diameter) is very large compared to the transistors that surround it (e.g., 20-40 nanometers). This difference in scale significantly affects routing, cell placement, and transistor stress, among many other design variables. Additionally, the embedded location of TSVs within dies and/or interposers, the smaller circuit/package footprint, and the more compact volume of 3D-ICs and packages, combine to increase the generation of heat and the resulting dissipation challenges. Moreover, the fabrication of TSVs is more complicated than conventional interconnect structures. These issues combine to make TSV-based systems more expensive than systems with conventionally interconnected components.